diff --git a/rerun_evaluator/src/rerun_evaluator/cli.py b/rerun_evaluator/src/rerun_evaluator/cli.py
new file mode 100644
index 0000000..4db2ec1
--- /dev/null
+++ b/rerun_evaluator/src/rerun_evaluator/cli.py
@@ -0,0 +1,75 @@
+import argparse
+import json
+import sys
+from pathlib import Path
+from typing import Any, List
+
+from rerun_evaluator.core import RunData, evaluate_rerun_needs
+
+
+def _load_runs_data(input_path: Path) -> List[RunData]:
+    try:
+        with input_path.open('r', encoding='utf-8') as f:
+            raw_data = json.load(f)
+        if not isinstance(raw_data, list):
+            raise ValueError('Input JSON must be a list of objects.')
+        runs_data = []
+        for idx, entry in enumerate(raw_data):
+            if not isinstance(entry, dict):
+                raise ValueError(f'Entry {idx} is not a dict.')
+            required_fields = {"run_id", "label_triggered", "flappy", "pinned", "unknown_rate"}
+            missing = required_fields - entry.keys()
+            if missing:
+                raise ValueError(f'Entry {idx} missing required fields: {missing}')
+            runs_data.append(
+                RunData(
+                    run_id=str(entry['run_id']),
+                    label_triggered=bool(entry['label_triggered']),
+                    flappy=bool(entry['flappy']),
+                    pinned=bool(entry['pinned']),
+                    unknown_rate=float(entry['unknown_rate'])
+                )
+            )
+        return runs_data
+    except (OSError, json.JSONDecodeError, ValueError) as e:
+        print(f'Error loading runs data: {e}', file=sys.stderr)
+        sys.exit(1)
+
+
+def _write_output(output_path: Path, result: Any) -> None:
+    try:
+        output_path.parent.mkdir(parents=True, exist_ok=True)
+        with output_path.open('w', encoding='utf-8') as f:
+            json.dump(result, f, indent=2)
+    except OSError as e:
+        print(f'Error writing output: {e}', file=sys.stderr)
+        sys.exit(1)
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(description='Evaluate Rerun Needs for CI Pipelines')
+    parser.add_argument('--input', required=True, help='Path to input JSON file with RunData entries.')
+    parser.add_argument('--output', required=True, help='Path to output JSON file for evaluation result.')
+    args = parser.parse_args()
+
+    input_path = Path(args.input)
+    output_path = Path(args.output)
+
+    if not input_path.exists():
+        print(f'Input file not found: {input_path}', file=sys.stderr)
+        sys.exit(1)
+
+    runs_data = _load_runs_data(input_path)
+    assert runs_data, 'Runs data list must not be empty.'
+
+    result = evaluate_rerun_needs(runs_data)
+
+    if not isinstance(result, dict):
+        print('Evaluation result must be a dict.', file=sys.stderr)
+        sys.exit(1)
+
+    _write_output(output_path, result)
+
+
+if __name__ == '__main__':
+    main()